Note: this is RFD900A

FD900A New Features:

New Processor, ARM 32 bit core.

Air data rate: 500kbit/s.



Packing list

RDF900A main modules *2

5DB SMA internal pin antennas * 4

USB line *1

UART connector line *2




main features

RDF900A is a wireless data transmission module with small volume and excellent performance. The main features are:

1. Regardless of transceiver design, each module is integrated with USB serial port chip, and USB and UART interfaces are automatically switched. USB takes precedence

2. Operating frequency range: 902-928 MHz, ISM band

3. The transmitting circuit is designed with a low-noise amplifier greater than 20DB, and a low-pass filter unit is added

4. The transmission power is adjustable, Maximum 1W transmit power

5. High sensitivity LNA and SAW circuits in front of receiving circuit

6. The outdoor communication distance can reach 40 km or more in a straight line (depending on antenna performance and communication rate requirements)

7. The air data rate can reach up to 250Kbps

8. Dual antenna interface, supporting antenna diversity and differentiated antenna configuration

9. Support AT command configuration of local radio station and RT command configuration of remote radio station

10. It has module temperature monitoring function and automatically adjusts the duty cycle according to the temperature to avoid overheating

11. Working temperature - 40 to + 85 ℃

12. The size is 33mm * 53mm * 9.5mm

13. Weight: 23g



Features:

Long range >40km depending on antennas and GCS setup *80km demonstrated by Edge Research labs on a balloon !, 57km in India, on Dipoles.
2 x RP-SMA RF connectors, diversity switched.
1 Watt (+30dBm) transmit power.
Transmit low pass filter.
> 20dB Low noise amplifier, high IP3.
RX SAW filter.
All I/O ESD protected and filtered.
Re implemented SiK and Multipoint SiK firmware, field upgradeable, easy to configure.
Compatible with 3DR / Hope-RF radio modules.



Interfaces:

RF : 2 x RP-SMA connectors
Serial: Logic level TTL (+3.3v)
Power: +5v, ~800mA max peak (at maximum transmit power)
GPIO: 6 General purpose IO (Digital, ADC, PWM capable).



Software / GCS Support:

The software solution is an open source development called "SiK". It has been re implemented to suit the new processor architecture available on the 32bit ARM processor core. A boot loader and interface is available for further development and field upgrade of the modem firmware via the serial port.
Most parameters are configurable via AT commands, Eg. baud rate (air/uart), frequency band, power levels.
Integrated support for configuring the RFD900 radios is supported by APM Planner.
The default settings are at 57600 baud, N, 8, 1, and 64k air data rate.



Software features include:

Frequency hopping spread spectrum (FHSS)
Transparent serial link

Point to Point, or Multipoint networking

Configuration by simple AT commands for local radio, RT commands for remote radio

User configurable serial data rates and air datarates

Error correction routines, Mavlink protocol framing (user selectable)
Mavlink radio status reporting (Local RSSI, Remote RSSI, Local Noise, Remote Noise)
Automatic antenna diversity switching on a packet basis in realtime
Automatic duty cycle throttling based on radio temperature to avoid overheating


Important note: please keep a distance of more than 3m when the two data transmission modules are powered on, otherwise it may cause abnormal frequency matching of data transmission and seriously burn the high-frequency circuit.